The organic compound which evaporates easily on exposure to atmospheric air

The well-known anaesthetic ether, also known as diethyl ether, is an organic chemical that is a member of the wide family of substances known as ether. Its molecular structure is made up of two ethyl groups joined by an oxygen atom, as in ${\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{OC}}_2{\mathrm{H}}_5$.